Reading...
Play button
Play button
Use LEFT and RIGHT arrow keys to navigate between flashcards;
Use UP and DOWN arrow keys to flip the card;
H to show hint;
A reads text to speech;
25 Cards in this Set
- Front
- Back
|
Antigen
|
a substance (usually foreign) which can elicit an immune response
|
|
|
Immunogenicity
|
ability of an antigen to stimulate production of an antibody
|
|
|
Innate immune response.
Examples. |
Saliva, skin, tears, normal flora
Natural and non-specific |
|
|
Acquired immune response.
|
Specific
Involves production of Abs |
|
|
5 factors that influence immunogenicity of an antigen.
|
1. Chemical composition
2. Degree of foreignness 3. Size 4. Dosage and antigen density 5. Route of administration |
|
|
Order of immunogenicity.
Composition. |
Protein > carbohydrates > Lipids
|
|
|
Order of immunogenicity.
Route of administration. |
IV or intramuscular > swallow
|
|
|
Most immunogenic blood group systems.
|
ABO > D > K
|
|
|
Properties of immunoglobulins.
|
- Proteins
- 2 light chains, 2 heavy chains - Heavy chain determines class of Ig - Variable regions are responsible for specificity |
|
|
Properties of IgM
|
- mu heavy chains
- 5 basic units held together with J chain - large pentamer - can't cross placenta - direct agglutination or rbcs |
|
|
Properties of IgG
|
- gamma heavy chain
- 1 basic unit - too small to produce direct agglutination - can cross placenta |
|
|
Percentage of IgG vs IgM
|
80% IgG
5-10% IgM |
|
|
Two situations which may lead to the production of red cell antibodies
|
Tranfusion
Pregnancy |
|
|
Properties of Primary Response
|
- first exposure
- lag phase of at least 5-7 days (up to 180 days) - small IgM response, followed by smalled IgG response, then both decline |
|
|
Properties of Secondary Response
|
- repeated exposure
- lag phase is 1-2 days - memory B cells recognize antigen - higher levels of Ig produced, last longer - mostly IgG, some IgM |
|
|
Two visible signs of ag-ab reaction in vitro
|
Hemolysis
Agglutination (usually) |
|
|
2 consequences of formation of ag-ab complex in vivo.
|
1. sensitization of red cells
- extravascular hemolysis 2. complement activated by ag-ab - extravascular hemolysis - intravascular hemolysis |
|
|
Sensitization of Red Cells.
Consequences. |
- extravascular hemolysis
- cleared by phagocytic cells of the RE system |
|
|
What organs are involved in the RE system?
|
*Spleen*
Liver Lungs Lymph nodes Bone marrow |
|
|
Complement activation.
Consequences. |
- activate cascade C1 to C9
- if proceed to C3 --> extravascular destruction or hemolysis - if proceed to C9 --> intravascular hemolysis (disruption of cell membrane) |
|
|
2 stages of hemagglutination.
|
Stage 1 - Sensitization
Stage 2 - Lattice formation |
|
|
Binding of Ab to Ag is affected by 5 factors.
|
1. serum to cell ratio
2. temp of reaction 3. incubation time 4. pH 5. ionic strength - decr'd ionic strength --> incr'd ag-ab binding |
|
|
Optimal reaction temp for IgM and IgG.
|
IgM: 20-22oC
IgG: 37oC |
|
|
What is lattice formation?
|
Cross-linkages result from random collisions and lead to visible clumping (aggregation)
|
|
|
Lattice formation is affected by?
|
1. distance between red cells (zeta potential)
2. [ab] and [ag] 3. centrifugation (forces rbc closer) |
